title: Specific chemical reactivities of spatially separated 3-aminophenol conformers with cold Ca+ ions.
abstract: Many molecules exhibit multiple rotational isomers (conformers) that interconvert thermally and are difficult to isolate. Consequently, a precise characterization of their role in chemical reactions has proven challenging. We have probed the reactivity of specific conformers by using an experimental technique based on their spatial separation in a molecular beam by electrostatic deflection. The separated conformers react with a target of Coulomb-crystallized ions in a trap. In the reaction of Ca(+) with 3-aminophenol, we find a twofold larger rate constant for the cis compared with the trans conformer (differentiated by the O-H bond orientation). This result is explained by conformer-specific differences in the long-range ion-molecule interaction potentials. Our approach demonstrates the possibility of controlling reactivity through selection of conformational states.
authors.affiliation: Center for Free-Electron Laser Science, Deutsches Elektronen-Synchrotron, Notkestrasse 85, 22607 Hamburg, Germany.
authors.forename: Yuan-Pin
authors.initials: YP
authors.lastname: Chang
authors.forename: Karol
authors.initials: K
authors.lastname: Długołęcki
authors.forename: Jochen
authors.initials: J
authors.lastname: Küpper
authors.forename: Daniel
authors.initials: D
authors.lastname: Rösch
authors.forename: Dieter
authors.initials: D
authors.lastname: Wild
authors.forename: Stefan
authors.initials: S
authors.lastname: Willitsch